When I took Lexie in to determine that she was PG for sure, my vet asked me if she was eating a high quality puppy food already (this was day 35ish) and that I should
feed her as much as she wants. So I would say yes you can increase her food intake at the point you are at and change over to puppy food for her. She needs to not only maintain her own diet, but supplement her growing puppies too. Good luck and let us know when you know for sure about her pregnancy.
